Governor signs executive order to adopt threat mitigation plan

Governor Lou Leon Guerrero signed an executive order Friday adopting the updated Guam Hazard Mitigation Plan for 2024.

Guam is regularly exposed to natural, man-made and technological disasters. Mitigation measures and responsible preparedness planning can be taken to limit the impact on the island, the executive order states.

The updated Guam Hazard Mitigation Plan for 2024 continues to demonstrate Guam’s commitment to reducing the risk of losses from natural and man-made hazards and serves as a strategic planning guide for decision-makers who allocate resources to mitigate the impacts of these hazards, the order stated.

The plan is a living document updated every five years. In the five years prior to the update, the plan should be implemented to the greatest extent possible to create an increasingly robust “all hazards” mitigation environment and a sustainable “all hazards” mitigation community on Guam, the plan states.

The plan outlines what Guam can expect in the coming decades regarding climate change.

“The air and oceans are warming, sea levels are rising, and the oceans are becoming more acidic,” the plan reads.

The plan says these changes will likely damage or destroy much of Guam’s coral reef ecosystems, increase damage from floods and typhoons, reduce the availability of freshwater during the dry season, and cause air temperatures to become more uncomfortably high than they are now.

Coral reefs

Warming waters will likely damage most corals around Guam. Average water temperatures around Guam have risen more than a degree over the past century, in addition to year-to-year changes related to the El Niño-Southern Oscillation.

Rising water temperatures are harming the algae that live inside corals and provide them with food. The loss of the algae weakens the corals and can ultimately kill them. This process is commonly known as “coral bleaching” because the loss of the algae also turns the corals white, the plan states.

Over the next 50 to 60 years, warming and acidification are likely to harm coral reefs around Guam and around the world, with widespread coral loss expected. Rising acidity would also reduce populations of shellfish and other organisms that depend on minerals in the water to build their skeletons and shells.

Warming and acidification could lead to serious damage to marine ecosystems and disruptions to the ecosystem services they provide to people.

Guam is home to a wide variety of fish species, many of which are caught for food and have cultural significance. Sharks, rays, catfish, snapper, and hundreds of other fish species rely on healthy coral reefs for habitat. The reefs also protect coastal fish nurseries and feeding grounds. A significant portion of the fish and invertebrates that inhabit the reefs are likely to lose their habitat by 2100.

Storms

As the climate changes, typhoons may cause more and more damage.

Guam is one of the most active regions in the world for tropical storms. In 2023, Typhoon Mawar caused about $300 million in damage, destroyed about 600 homes, left the island without power and left many without water.

In 2002, Typhoon Pongsona caused $700 million in damage, destroyed 1,300 homes, and left the island without electricity. In recent years, the neighboring islands have suffered some of the strongest and most destructive tropical cyclones ever recorded, including Super Typhoons Haiyan (2013), Maysak (2015), and Soudelor (2015).

Although the frequency of tropical cyclones is projected to decrease, wind speeds and rainfall intensity during typhoons are likely to increase as the climate warms, which would increase the intensity of tropical cyclones reaching Guam, the plan stated.

Climate change is a concern for all hazards in the plan, except earthquakes, non-seismic landslides, and terrorism. Two of these hazards are not climate-related, as two are related to Guam’s geology and the others are human-caused.

Rising sea levels

According to the plan, sea level has risen about ten centimeters (3 inches) since 1993 relative to Guam’s shoreline.

If the oceans and atmosphere continue to warm, sea levels around Guam will rise by 30 to 90 cm over the next century.

Sea level rise is flooding low-lying areas, eroding beaches, and increasing coastal flooding from typhoons and tsunamis. Homes and coastal infrastructure will be more likely to flood as sea levels rise because storms will also intensify.

Guam’s homes, businesses, roads and port are vulnerable to storm surges and rising sea levels.

Dry, warmer

Guam’s wet season could become wetter, while dry periods could become drier. Although Guam recorded its second-highest rainfall in 2023, Guam is expected to become drier overall in the long term, with a projected decrease in wet season precipitation across the island.

Warmer temperatures tend to increase rainstorms and droughts. In addition, Guam’s climate tends to be dry during El Niño years and wet during La Niña years, and scientists generally expect the differences between El Niño and La Niña years to become more significant in most places.

Hot days can be unhealthy and even dangerous. Rising temperatures will increase the frequency of hot days and warm nights. High air temperatures can cause heat stroke and dehydration and affect the cardiovascular and nervous systems of people. Warm nights are dangerous because they prevent the human body from cooling down after a hot day.

Some people are particularly vulnerable, including children, the elderly, the sick and the poor.

“Climate change is expected to disrupt many aspects of Guam, and vulnerable populations will be disproportionately affected,” the plan states.